Fast lithiation of NiO investigated by in situ transmission electron microscopy

As a lithium-ion battery anode material, NiO has attracted a lot of attention owing to its excellent theoretical capacity. In this work, the dynamic lithiation process of NiO nanoplates and nanoparticles was investigated by in situ transmission electron microscopy (TEM). The morphology evolution, phase transformation, and electrochemical reaction of NiO during the lithiation process have been probed in real time by in situ TEM combined with selected area electron diffraction and electron energy loss spectroscopy technologies. We found that the insertion of Li-ions led to huge volume expansion of NiO, resulting in structural changes and breakdown. Li2O formed during lithiation hinders electron transportation through NiO due to its low conductivity, which causes poor cycling performance of NiO. Our findings provide valuable theoretical guidance for the modification of NiO as anode material for next generation high-performance lithium-ion batteries.